U.S. patent number 8,356,425 [Application Number 10/585,085] was granted by the patent office on 2013-01-22 for breathable waterproof sole for shoes.
This patent grant is currently assigned to GEOX S.p.A.. The grantee listed for this patent is Antonio Ferrarese, Bruno Mattioni, Mario Polegato Moretti. Invention is credited to Antonio Ferrarese, Bruno Mattioni, Mario Polegato Moretti.
United States Patent |
8,356,425 |
Polegato Moretti , et
al. |
January 22, 2013 |
Breathable waterproof sole for shoes
Abstract
A waterproof breathable sole for shoes, which comprises, for at
least part of its extension, at least two structural layers, a
lower one provided with a supporting structure so as to form the
tread, and an upper one that is permeable to water vapor. The lower
layer has portions that are open onto the upper layer. A coating
obtained by means of a plasma deposition treatment for
waterproofing is provided on the upper layer. A layer is thus
obtained that has structural functions and characteristics of
resistance to damage and is at the same time waterproof and
breathable.
Inventors: |
Polegato Moretti; Mario
(Crocetta del Montello, IT), Ferrarese; Antonio
(Isola Della Scala, IT), Mattioni; Bruno (Udine,
IT) |
Applicant: |
Name |
City |
State |
Country |
Type |
Polegato Moretti; Mario
Ferrarese; Antonio
Mattioni; Bruno |
Crocetta del Montello
Isola Della Scala
Udine |
N/A
N/A
N/A |
IT
IT
IT |
|
|
Assignee: |
GEOX S.p.A. (Montebelluna,
IT)
|
Family
ID: |
34717642 |
Appl.
No.: |
10/585,085 |
Filed: |
December 27, 2004 |
PCT
Filed: |
December 27, 2004 |
PCT No.: |
PCT/EP2004/014717 |
371(c)(1),(2),(4) Date: |
April 30, 2007 |
PCT
Pub. No.: |
WO2005/063069 |
PCT
Pub. Date: |
July 14, 2005 |
Prior Publication Data
|
|
|
|
Document
Identifier |
Publication Date |
|
US 20070271815 A1 |
Nov 29, 2007 |
|
Foreign Application Priority Data
|
|
|
|
|
Dec 30, 2003 [IT] |
|
|
PD2003A0312 |
|
Current U.S.
Class: |
36/3B; 428/317.9;
36/3R; 36/98; 36/30R |
Current CPC
Class: |
A43B
7/06 (20130101); A43B 23/0235 (20130101); A43B
7/087 (20130101); A43B 9/02 (20130101); A43B
13/125 (20130101); A43B 7/125 (20130101); A43B
7/08 (20130101); A43B 13/026 (20130101); A43B
13/12 (20130101); B05D 1/62 (20130101); Y10T
428/249986 (20150401) |
Current International
Class: |
A43B
7/06 (20060101); A43B 13/12 (20060101); A43B
23/07 (20060101) |
Field of
Search: |
;36/98,3R,3B,3A,30R,25R
;428/319,319.7,316.6,317.9,315.5,315.7 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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0 275 644 |
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Jul 1988 |
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EP |
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0 985 741 |
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Mar 2000 |
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EP |
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1 197 158 |
|
Apr 2002 |
|
EP |
|
63-140437 |
|
Jun 1988 |
|
JP |
|
63-115304 |
|
Jul 1988 |
|
JP |
|
06-299331 |
|
Oct 1994 |
|
JP |
|
10-234414 |
|
Sep 1998 |
|
JP |
|
2000-166606 |
|
Jun 2000 |
|
JP |
|
2000-175701 |
|
Jun 2000 |
|
JP |
|
2002-524660 |
|
Aug 2002 |
|
JP |
|
2003-521588 |
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Jul 2003 |
|
JP |
|
2003-235604 |
|
Aug 2003 |
|
JP |
|
WO 97/14326 |
|
Apr 1997 |
|
WO |
|
WO 01/12004 |
|
Feb 2001 |
|
WO |
|
WO 01/78542 |
|
Oct 2001 |
|
WO |
|
2004 004504 |
|
Jan 2004 |
|
WO |
|
Other References
US. Appl. No. 10/565,541, filed Jan. 23, 2006, Polegato Moretti.
cited by applicant .
Japanese Office Action issued Sep. 21, 2010, in Patent Application
No. 2006-546085 (with English-language translation). cited by
applicant .
European Search Report as received in the corresponding European
Patent Application No. 09157715.5-2318/2168448 dated Jul. 1, 2011.
cited by applicant .
Office Action dated Feb. 14, 2012 as received in the corresponding
European Patent Application No. 04 804 307.9-2318. cited by
applicant .
Dirk Hegemann, et al. "Plasma Treatment of Polymers to Generate
Stable, Hydrophobic Surfaces", Plasmas and Polymers, vol. 6, No. 4,
Dec. 2001, pp. 221-235. cited by applicant .
U.S. Appl. No. 13/091,355, filed Apr. 21, 2011, Polegato Moretti,
et al. cited by applicant .
Office Action issued Mar. 13, 2012 in Japanese Patent Application
No. 2006-546085 (English translation only). cited by applicant
.
Office Action as received in the corresponding Japanese Patent
Application No. 2006-546085 dated Oct. 23, 2012. cited by
applicant.
|
Primary Examiner: Mohandesi; Jila M
Attorney, Agent or Firm: Oblon, Spivak, McClelland, Maier
& Neustadt, L.L.P.
Claims
The invention claimed is:
1. A waterproof breathable sole for shoes, comprising, for at least
part of its extension, at least two structural layers, wherein a
first structural layer is a lower layer provided with a supporting
structure so as to form a tread, and a second structural layer is
an upper microporous layer that is permeable to water vapor, said
lower layer having two, upper and lower surfaces and portions that
are open onto said upper layer, and wherein at least one of two
surfaces of said upper layer comprises a coating formed by plasma
deposition treatment for waterproofing, wherein said lower layer is
constituted by a perimetric skirt that constitutes an outer edge of
the sole, and by ground contact elements, which are made so as to
support said upper layer, and wherein spaces of said lower layer
comprised between each one of said ground contact elements, and
between said ground contact elements and said skirt, form said
portions.
2. The sole according to claim 1, wherein said coating is provided
on the upper surface of said upper layer.
3. The sole according to claim 1, wherein said coating is provided
on the lower surface of said upper layer.
4. The sole according to claim 1, wherein said coating is provided
both on the lower surface and on the upper surface of said upper
layer.
5. The sole according to claim 1, wherein said upper layer and said
lower layer are joined hermetically along a perimeter region
thereof in order to avoid water infiltrations.
6. The sole of claim 5, wherein said upper layer is made of
sintered plastic material.
7. The sole according to claim 6, wherein said sintered plastic
material is polyethylene, polypropylene, polystyrene or
polyester.
8. The sole according to claim 1, wherein said upper layer is
selected from a group of materials comprising a felt, a fleece, a
fabric and mesh made of synthetic material.
9. The sole according to claim 1, wherein said upper layer has an
average pore width between 3 and 250 .mu.M.
10. The sole according to claim 1, wherein said upper layer is
hydrophobic.
11. The sole of claim 1, wherein said plasma deposition treatment
is a high-vacuum cold plasma treatment.
12. The sole of claim 11, wherein said plasma deposition treatment
is carried out with a radiofrequency generator so that a treatment
electrical field oscillates with a frequency substantially between
13 MHz and 14 MHz.
13. The sole of claim 11, wherein said plasma deposition treatment
is carried out with a radiofrequency generator so that a treatment
electrical field oscillates with a frequency preferably on the
order of 13.56 MHz.
14. The sole of claim 12, wherein said plasma deposition treatment
is carried out with a power of the treatment electrical field that
is substantially between 50 and 700 W.
15. The sole of claim 11, wherein a duration of said plasma
deposition treatment for a siloxane-based monomer coating is
between 160 seconds and 600 seconds.
16. The sole according to claim 15, wherein a duration of said
plasma deposition treatment for a siloxane-based monomer coating is
substantially equal to 420 seconds.
17. The sole of claim 11, wherein a vacuum level in said plasma
deposition treatment is substantially between 10.sup.-1 mbar and
10.sup.-5 mbar.
18. The sole according to claim 1, wherein said plasma deposition
treatment is a high-vacuum cold plasma treatment applied with a
radiofrequency generator so that a treatment electrical field
oscillates with a frequency on the order of 13.56 MHz, with an
applied electrical field power equal to 50-700 W and a vacuum level
between 10.sup.-1 mbar and 10.sup.-5 mbar.
19. The sole of claim 18, wherein a precursor material of the
plasma deposition is a siloxane-based monomer.
20. The sole of claim 18, wherein a precursor material of the
plasma deposition is an oil-repellent and water-repellent
fluoropolymer.
21. The sole according to claim 1, wherein a material of said
coating is a polysiloxane.
22. The sole according to claim 1, wherein a material of said
coating is an oil-repellent and water-repellent fluoropolymer.
23. The sole according to claim 22, wherein said fluoropolymer is a
commercially available material.
24. The shoe of claim 1, wherein said microporous upper layer that
is permeable to water vapor is made of leather.
25. A waterproof breathable sole for shoes, comprising, for at
least part of its extension, at least two structural layers,
wherein a first structural layer is a lower layer provided with a
supporting structure so as to form a tread, and a second structural
layer is an upper microporous layer that is permeable to water
vapor, said lower layer having two, upper and lower surfaces and
portions that are open onto said upper layer, and wherein at least
one of two surfaces of said upper layer comprises a coating formed
by plasma deposition treatment for waterproofing, wherein said
upper layer and said lower layer are joined hermetically along a
perimeter region thereof in order to avoid water infiltrations,
wherein said lower layer is constituted by a perimetric skirt that
constitutes an outer edge of the sole, and by ground contact
elements, which are made so as to support said upper layer, and
wherein spaces of said lower layer comprised between each one of
said ground contact elements, and between said ground contact
elements and said skirt, form said portions, wherein said plasma
deposition treatment is a high-vacuum cold plasma treatment applied
with a radiofrequency generator so that a treatment electrical
field oscillates with a frequency on the order of 13.56 MHz, with
an applied electrical field power equal to 50-700 W and a vacuum
level between 10.sup.-1 mbar and 10.sup.-5 mbar, and wherein a
precursor material of the plasma deposition is an oil-repellent and
water-repellent fluoropolymer.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a 371 of PCT/EP04/14717 filed Dec. 27, 2004 and
claims the benefit of Italian application PD2003A000312 filed Dec.
30, 2003.
TECHNICAL FIELD
The present invention relates to a breathable waterproof sole for
shoes.
BACKGROUND ART
The present invention also relates to a shoe manufactured with such
sole.
It is known that the footwear market is continuously evolving in
order to seek and identify technical solutions that ensure optimum
comfort for the end-user of the shoe.
As is well known, the comfort of a shoe depends not only on a
correctly anatomical fit but also on correct outward permeation of
the water vapor generated inside the shoe due to perspiration, in
order to avoid the so-called "wet foot" phenomenon.
However, this water vapor permeation must not compromise the
waterproofness of the shoe, and therefore solutions have been
studied which entrust permeation to the upper or to the sole.
Most of the perspiration of the foot is produced at the interface
between the sole of the foot and the sole of the shoe, and it is
evident that the sweat that forms there is unable to evaporate and
therefore condenses on the insole on which the foot rests. Only a
minimal fraction of the sweat evaporates through the upper.
This problem is particularly important in shoes that have a plastic
sole; in these cases, permeation through the sole is completely
prevented (in the case of leather soles there is instead a small
amount of permeation).
Solutions to the problem are provided by breathable and waterproof
soles, which accordingly allow permeation of the sweat generated at
the sole of the foot.
One of these solutions is disclosed in U.S. Pat. No. 5,044,096 and
in EP-0382904 and consists in dividing the plastic sole into two
layers with through holes and in interposing a waterproof
breathable membrane (for example made of a material such as
Gore-Tex.RTM. or the like), which is joined perimetrically and
hermetically to the two layers, so as to allow no infiltrations of
water.
This solution ensures correct permeation as well as an effective
exchange of heat and water vapor between the environment inside the
shoe and the outside environment, at the same time ensuring the
necessary impermeability with respect to external moisture and
water.
These perforated soles provided with waterproof and breathable
membranes have certainly constituted a considerable innovation with
respect to what was previously available.
Nonetheless, there are still aspects that can be improved,
particularly in relation to the area occupied by the holes.
As is evident, the larger the total hole area, the greater the
breathability; however, on the other hand, the number of holes
provided in the tread and their diameter must be limited in order
to prevent pointed foreign objects from entering through the holes
and penetrating until they damage or pierce the membrane, which is
delicate, since in practice it is a film and lacks adequate
structural characteristics.
Such membrane is in fact continuously subjected to the compression
performed by the foot, and therefore even a body that is not
particularly pointed that penetrates one of the holes may cause
damage without excessive difficulty.
One solution that has been adopted is to use a breathable
protective layer, such as a felt, between the tread and the
membrane.
Moreover, dirt, dust and pebbles may wedge in the holes of the
tread, obstructing them and thus limiting breathability.
A different solution with respect to the use of a waterproof and
breathable membrane lacking structural characteristics is disclosed
in U.S. Pat. No. 6,508,015.
This patent discloses a sole that is provided by a structure with
two layers, respectively an elastic upper layer, which is permeable
to water vapor, and a lower layer, which covers less than 70% of
the upper layer, which also acts as a support and as a tread.
The permeation activity of the sole is ensured by the microporous
structure of the upper layer and by the shape of the lower
layer.
The microporous structure of the upper layer is provided for
example by means of sintered plastic material or by means of woven
or non-woven structures made of synthetic material.
However, this layer does not have strictly waterproof
characteristics; for this purpose, the patent mentions the
possibility of rendering this layer hydrophobic, for example by
treating the sintered polyethylene in high or ultra-high molecular
weight conditions.
Another possibility for the waterproofing disclosed in the patent
is to add, above the upper layer, an additional layer formed by a
waterproof membrane.
Although this described solution solves the problem of the
breathable area of the sole, which is large, it does not adequately
meet the requirement of waterproofing said sole.
It has in fact been found that the hydrophobic treatment of the
sintered material does not make the upper layer sufficiently
waterproof, especially in the case of large amounts of water.
Moreover, the idea of coupling an impermeable membrane to the inner
layer is not in itself sufficient to ensure perfect insulation from
water, since infiltrations of water along the perimeter of the
upper layer are possible.
Another problem that is linked to this type of sole is that the
upper layer tends in any case to absorb considerable amounts of
water ("sponge effect"), which is released over time, leading to
evident soiling of the surfaces on which one walks.
This problem becomes more evident as the size of the pores of the
material increases.
Already for pore dimensions of more than 5 .mu.m, there is
penetration of unclean water (dirty or soapy water): in this case,
the surface tension is lower than the typical value of water (73
mN/mm).
DISCLOSURE OF THE INVENTION
The aim of the present invention is to provide a breathable
waterproof sole for shoes that solves the problems noted in known
soles.
Within this aim, an object of the present invention is to provide a
breathable waterproof sole for shoes that uses a waterproof and
breathable structural layer and at the same time ensures higher
breathability than known shoes.
Another object of the present invention is to provide a breathable
waterproof sole for shoes that is resistant to wear and damage.
Another object of the present invention is to provide a breathable
and waterproof sole for shoes that is composed of a smaller number
of components than known soles.
Another object of the present invention is to provide a breathable
and waterproof sole for shoes that can be manufactured with known
systems and technologies.
This aim and these and other objects that will become better
apparent hereinafter are achieved by a waterproof breathable sole
for shoes comprising, for at least part of its extension, at least
two structural layers, a lower one provided with a supporting
structure so as to form the tread, and an upper microporous one
that is permeable to water vapor, said lower layer having portions
that are open onto said upper layer, said sole being characterized
in that at least one of the two surfaces of said upper layer has a
coating obtained by means of a plasma deposition treatment for
waterproofing.
BRIEF DESCRIPTION OF THE DRAWINGS
Further characteristics and advantages of the invention will become
better apparent from the description of some preferred but not
exclusive embodiments thereof, illustrated by way of non-limiting
example in the accompanying drawings, wherein:
FIG. 1 is a transverse sectional view of a portion of a shoe with a
sole according to the invention;
FIG. 2 is a transverse sectional view of a detail of a sole
according to FIG. 1;
FIG. 3 is a view of a detail of a variation of the sole shown in
FIG. 1;
FIG. 4 is a plan view of the sole of FIG. 1;
FIG. 5 is a plan view of another variation of the sole of FIG.
1;
FIG. 6 is a transverse sectional view of a portion of a shoe with
an embodiment of the sole according to the invention that is
alternative with respect to the embodiments of the previous
figures;
FIG. 7 is a perspective view of a shoe with a sole according to the
invention;
FIG. 8 is a transverse sectional view of a portion of another shoe
according to the invention, which is alternative with respect to
the shoes of the preceding figures;
FIG. 9 is a transverse sectional view of a portion of another shoe
according to the invention, which is alternative with respect to
the shoes of the preceding figures.
WAYS OF CARRYING OUT THE INVENTION
With reference to the figures, a first embodiment of the sole
according to the invention is generally designated by the reference
numeral 10.
FIG. 1 is a transverse sectional view of a shoe related to the
region of the sole 10; this figure clearly shows that the sole 10
comprises, in this embodiment, two layers, which compose
respectively a lower layer 14 and an upper layer 15 that is
permeable to water vapor.
Both of the layers 14 and 15 are structural and therefore have a
supporting function; in particular, the lower layer 14 has a
supporting structure so as to form the tread of the sole 10, while
the upper layer 15 forms the foot supporting base and has
elasticity and flexibility characteristics.
In order to allow breathability of the upper layer 15, the lower
layer 14 has portions 14a that are open onto the upper layer 15, so
that it is exposed directly to the external environment; such open
portions 14a are described in greater detail hereinafter.
The upper layer is microporous and is for example made of sintered
plastics material.
Conveniently, the plastics material that is used can be any of
polyethylene, polypropylene, polystyrene or polyester.
Optionally, the upper layer 15 can be constituted by any of a felt,
a fleece, a fabric or mesh, made of synthetic material.
In order to ensure adequate permeability to water vapor and allow
subsequent surface treatments of the upper layer 15 (as described
hereinafter), the average width of the pores is comprised between 3
and 250 .mu.m.
Preferably, the average width can be comprised between 3 and 5
.mu.m.
The lower layer 14 is made of plastics, such as for example
polyurethane.
The lower layer 14 is constituted by a perimetric skirt 16 that
constitutes the outer edge of the sole, and by ground contact
elements 17, which act as a support for the upper layer 15 (which
otherwise would collapse within the perimeter of the skirt).
The spaces of the lower layer 14 that are comprised between the
various ground contact elements 17 and between the ground contact
elements and the skirt 16 form the portions 14a.
In this embodiment, the perimetric skirt 16 has a lateral portion
18 that includes a perimetric contour 19 of the upper layer 15 so
as to form perimetric regions of mutual contact 20 between layers
14 and 15.
In this lateral portion 18, the upper layer 15 and the lower layer
14 are hermetically joined along their perimeter in order to avoid
infiltrations of water.
Preferably, the coupling between the layers 14 and 15 occurs by
overmolding the lower layer 14 onto the upper layer 15; in this
case, hermetic complete coupling is ensured by the perfect adhesion
provided by overmolding.
As an alternative, it is possible to use other production methods,
such as for example adhesive bonding methods; in this case,
however, the coupling of the upper layer 15 to the lower layer 14
provides for sealant in the perimetric regions of mutual contact
20.
The ground contact elements 17, in this described embodiment, are
separated from the skirt 16 and are provided for example by
overmolding directly on the lower surface 15a of the upper layer
15, so as to form in practice studs 17a that supports the upper
layer 15 and ensure the grip of the sole 10.
Variations of these ground contact elements, now designated by the
reference numeral 117 in FIG. 5, provide for example continuous
transverse elements 117a, which are provided monolithically with
the skirt 116.
The portions 114a are formed between the transverse continuous
elements 117a and the skirt 116.
For correct permeation, it is important that the lower layer cover
the smallest possible extent of the upper layer.
For example, conveniently, the lower layer can cover a percentage
of the upper layer that is comprised between 30% and 70%.
The upper layer 15 has, on its upper surface 15b, a coating 21
obtained by means of a plasma deposition treatment, which allows
waterproofing (and also maintains breathability).
As an alternative, as shown in FIG. 3, it is possible to provide a
coating, designated by the reference numeral 221, which is obtained
by means of a plasma deposition treatment on a lower surface 215a
of a lower layer 215.
It is optionally possible to provide such coating on both of the
surfaces of the lower layer 15,215.
The idea of coating by plasma deposition arises from the surprising
experimental discovery that a vapor of a siloxane organic compound
can be used to produce an ultrathin layer on a microporous
supporting material by "cold plasma" polymerization in high vacuum
at ambient temperature, providing waterproofing characteristics
without altering the general characteristics and in particular the
breathability characteristics of the supporting material.
A waterproof and breathable membrane can in fact be created by
plasma polymerization for example of a monomer based on siloxane by
depositing a layer of polymer (polysiloxane) on a microporous
supporting material (made for example of polyethylene or
polystyrene).
This deposition can also be performed for example by using
oil-repellent and water-repellent fluoropolymers, such as those
manufactured by DuPont and registered with the trade name
Zonyl.RTM..
Plasma is divided into hot and cold depending on the temperatures
that it reaches; it is also divided into ambient-pressure plasma
and vacuum plasma.
In a plasma process for obtaining a coating according to the
present invention, a gaseous or vaporized precursor compound is
introduced in a reaction chamber at a very low pressure (in vacuum
conditions).
A plasma condition is generated by energizing the precursor within
the reaction chamber by generating an electrical field.
The result is an ultrathin bonded layer of the polymer deposited on
the entire surface of any substrate material introduced in the
reaction chamber.
The plasma polymerization process is started and performed by means
of an electrical field so as to achieve breakdown of the precursor
of the deposition layer inside the reaction chamber.
Once breakdown has occurred, ions and reactive species are formed
which begin and assist the atomic and molecular reactions that lead
to the formation of thin films.
Layers created by plasma polymerization may use various
configurations of electrical fields and different reaction
parameters.
The thickness of the layer is controlled by selecting the
polymerizable initial material and the reaction conditions, such as
the monomer deposition time, the treatment time, the electrical
frequency at which the reaction is performed, and the power that is
used.
In the present invention, plasma polymerization is performed in
vacuum.
The typical range of pressures is between 10.sup.-1 and 10.sup.-5
mbar.
The precursor is typically reacted in its pure state, by using a
non-polymerizable inert gas, such as for example argon; such inert
gas is used both as an inert diluent and as a carrier gas that
assists polymerization of the precursor.
Other gases that can be used are oxygen, helium, nitrogen, neon,
xenon and ammonia.
The precursor must have a vapor pressure that is sufficient to
allow vaporization in a moderate vacuum.
A reaction sequence generally begins by loading the support
material to be coated into the reaction chamber and subsequently
bringing the chamber to the intended vacuum pressure.
The plasma generating discharge is produced and the vaporized
precursor monomer is injected into the reaction chamber.
Collision of the monomer with the ions and electrons of the plasma
allows polymerization of the monomer.
The resulting polymer is deposited on the exposed surfaces inside
the chamber.
The properties of the film are not only a function of the structure
of the monomer but are also a function of the discharge frequency,
of the power used, of the flow-rate of the monomer and of the
pressure.
Porosity, surface morphology and permeability may vary according to
the reaction conditions.
An important variable in the plasma polymerization reaction is the
rate of deposition of the polymer, which can be changed by means of
the flow-rate of the monomer.
The deposition process ends when the intended thickness of
deposited material is reached.
Thanks to the fact that the upper layer 15 is made of insulating
material (for example, polyethylene is one of the most highly
insulating materials known), in order to maintain the plasma
conditions it is necessary to apply to the process a radiofrequency
generator, so that the electrical field in the treatment oscillates
with a frequency on the order of 13.56 MHz, with an applied
electrical field power of 50-700 W and a vacuum level comprised
between 10.sup.-1 and 10.sup.-5 mbar.
The microporous upper layer 15 must have an average pore width
comprised between 3 and 250 .mu.m.
As regards the duration of the treatment, it has been studied that
for a precursor such as a siloxane monomer the optimum time is
comprised substantially between 160 and 600 seconds; in particular,
an optimum duration of substantially 420 seconds has been
found.
Regardless of the plasma deposition treatment, it is further
possible to render the upper layer 15 hydrophobic by treating for
example the sintered polyethylene in high- or ultra-high molecular
weight conditions.
FIG. 6 is a view of a portion of a shoe with an alternative
embodiment of a sole, generally designated here by the reference
numeral 300, which uses a waterproof membrane 321.
In practice, as in the preceding case, the sole 300 comprises a
lower structural layer 314 with a supporting structure so as to
form the tread and an upper microporous structural layer 315 that
is permeable to water vapor: the lower layer 14 is provided with
portions 314a that are open onto the upper layer 315 in order to
allow breathability.
The waterproof membrane 321 is coupled in an upward region to the
upper structural layer 315.
The upper layer 315 has structural functions for supporting the
foot and functions for protecting the waterproof membrane 321.
In this case, however, the upper layer 315 and the waterproof
membrane 321 must be hermetically joined along their perimeter in
order to prevent water infiltrations.
As already known, the waterproof membrane 321 can optionally be
coupled (so as to withstand hydrolysis without compromising
breathability), with a supporting mesh (not shown in the figures,
since it is a known element) made of synthetic material.
The membrane 321 can be fixed to the upper layer 315, for example,
by lamination directly onto the upper layer 315 or can be fixed
subsequently by adhesive spots according to methods that are per se
known.
As previously, the coupling between the lower layer 314 and the
upper layer 315 with the membrane 321 coupled thereto preferably
occurs by overmolding the lower layer 314 onto the assembly
constituted by the upper layer 315 and the membrane 321; in this
case, the hermetic coupling is ensured by the perfect adhesion
provided by overmolding.
As an alternative, it is possible to use other production methods,
such as for example adhesive bonding techniques; in this case,
however, sealant is provided along the perimeter where the membrane
makes contact with the directly overlying layer.
FIG. 7 illustrates a shoe 11 that is constituted by a sole 10,300,
as described in one of the previous examples, by an upper 12, and
by an insole 13.
FIG. 8 illustrates a breathable and waterproof shoe 411, which
comprises an assembly 401 that wraps around the foot insertion
region like a pouch and is constituted by a breathable upper 412
with which a waterproof membrane 421 is associated in a downward
region.
A sole 400 is associated below the assembly 401 and comprises, like
the sole examples described earlier, two component layers,
respectively a lower layer 414 and an upper layer 415, which is
microporous and permeable to water vapor.
Both of said layers 414 and 415 are structural and therefore have a
supporting function; in particular, the lower layer 414 has a
supporting structure so as to form the tread of the sole 400, while
the lower layer 415 forms the foot supporting base and has
elasticity and flexibility characteristics.
In order to allow breathability of the upper layer 415, the lower
layer 414 has portions 414a that are open onto said upper layer
415, so that it is directly exposed to the outside environment.
In this embodiment, the assembly 401 is composed of the upper 412
and of a breathable or perforated insole 413, which is joined by
means of stitches 402 to the edges of said upper 412 according to
the per se known "strobel" or "ideal welt" structure so as to form
a pouch.
In this embodiment, the waterproof membrane 421 adheres only to the
insole 413 and can be applied for example by direct lamination onto
the insole before sewing to the upper 412 or can be applied
subsequently for example by spot gluing.
In order to avoid water infiltration problems, the assembly 401
comprises, along the perimeter of the waterproof membrane 421, a
sealing area 421a that straddles the stitched seams 402 and said
membrane 421, reaching the upper layer 415.
An alternative embodiment with respect to the shoe 411 is described
in FIG. 9 and is generally designated by the reference numeral
511.
The differences with respect to the embodiment of the shoe 411
substantially relate only to the part related to the assembly, here
designated by the reference numeral 501, that surrounds in a
pouch-like manner the foot insertion region and with which a sole
500 is associated in a downward region which is composed of a lower
layer 514 and an upper layer 515 such as the ones described
previously.
Such pouch is sealed and rendered waterproof according to known
techniques.
The assembly 501 is composed of an upper 512, which is externally
coupled to the sole 500 by means of its lower edges 512a and is
internally coupled to a waterproof membrane 521, which forms a
pouch for containing foot insertion.
The waterproof membrane 521 is fixed for example to the upper 512
by spot gluing, so as to avoid compromising breathability through
said upper.
An inner sheet of fabric 521a is coupled to the waterproof membrane
521 toward the inside of the shoe and together with said membrane
forms the inner lining of the shoe.
In this case also, the coupling of the assembly 501 to the sole 500
occurs by means of per se known techniques, such as for example
direct overmolding of the sole, adhesive bonding, et cetera.
Advantageously, in all of the described embodiments (except for
those in which another material is explicitly required for
construction reasons), the upper microporous layer that is
permeable to water vapor (15, 215, 315, 415, 515) can be made of
leather.
In practice it has been observed that the invention thus described
solves the problems noted in known types of sole for shoes; in
particular, the present invention provides a breathable and
waterproof sole that has a structural element, the upper layer,
which in addition to performing foot supporting functions is also
designed to ensure breathability and waterproofing, since it is
directly exposed to the outside environment.
Waterproofing has been ensured by the coating of the upper layer
obtained by means of the plasma treatment.
In this manner, the characteristic of waterproofing has been
associated with a structural component of the sole (the upper
layer) that has breathability characteristics.
The structural characteristic and the strength of the upper layer
allows to prevent foreign pointed objects from penetrating to the
point of damaging or piercing it and therefore from rendering the
waterproofing substantially useless.
In this manner, it is possible to ensure a large surface (the part
of the upper layer that is not covered by the lower layer) for
breathability of the sole, considerably reducing the possibility of
condensation of water vapor inside a shoe.
By using plasma deposition, the problems of conformity and adhesion
of a thin film to a support are solved, since the polymer adheres
to the support for a longer time than conventional spreading
(typically, the waterproof membranes that are currently used are
produced separately and then bonded by spot gluing or laminated or
spread directly onto the support).
With this plasma deposition, it is possible to create an extremely
thin deposition layer on the supporting material, even on the order
of 100 Angstrom.
The selection of the sintered plastic material for providing said
upper layer, moreover, allows the necessary flexibility of the sole
and allows to overmold the tread in an optimum manner.
In one described embodiment, preference has been given to using,
instead of coating by plasma deposition, a waterproof membrane
coupled to the upper breathable layer.
In this case, the invention solves the problems of known shoes that
use such sole structures, by joining perimetrically and
hermetically the waterproof membrane and the upper breathable
layer.
In the last three embodiments described, the invention has
advantageously combined a supporting sole structure, which has
large areas for vapor permeation toward the ground, with an
assembly that forms a pouch for foot insertion that is completely
breathable (both laterally and in a downward region) and is
impermeable at least in the direction of the sole; in particular,
in the shoes designated by the reference numerals 500 and 600, a
pouch for foot insertion that is completely breathable and
impermeable has been obtained.
In all of the embodiments provided with a membrane described above,
the upper layer continues to have structural supporting functions
as well as a membrane protection functions.
The invention thus conceived is susceptible of numerous
modifications and variations, all of which are within the scope of
the appended claims; all the details may further be replaced with
other technically equivalent elements.
In practice, the materials used, so long as they are compatible
with the specific use, as well as the dimensions, may be any
according to requirements and to the state of the art.
The disclosures in Italian Patent Application no. PD2003A000312,
from which this application claims priority, are incorporated
herein by reference.
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